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NIST Authors in Bold

Displaying 4676 - 4700 of 74129

Quantum Blackbody Thermometry

April 22, 2021
Author(s)
Eric B. Norrgard, Stephen Eckel, Christopher L. Holloway, Eric L. Shirley
Blackbody radiation (BBR) sources are calculable radiation sources that are frequently used in radiometry, temperature dissemination, and remote sensing. Despite their ubiquity, blackbody sources, have a plethora of systematics (e.g., emissivity

Recent research and development in photometry at NIST

April 22, 2021
Author(s)
Yuqin Zong, Maria Nadal, Benjamin K. Tsai, C Cameron Miller
Many developments were made in recent years in photometry at NIST for reducing measurement uncertainties, increasing calibration efficiencies, and adding measurement capabilities. The 40 years old photometry laboratory has been renovated. The new

Spatial frequency domain Mueller matrix imaging

April 22, 2021
Author(s)
Joseph Chue-Sang, Aaron Goldfain, Jeeseong C. Hwang, Thomas A. Germer
We combine Mueller matrix polarimetry (MMP) with spatial frequency domain imaging (SFDI) to create a technique that is sensitive to near-surface material anisotropy. We demonstrate this imaging modality with scattering and absorbing phantoms and with a

STANDARD LEDS WITH SUPERIOR LONG-TERM STABILITY

April 22, 2021
Author(s)
Yuqin Zong, Weiqiang Zhao, C Cameron Miller
A large-chip standard LED with superior long-term stability have been developed at NIST. The standard LED uses a large, specialty die rated for 50 W but is operated under 3 W to eliminate aging effect. The standard LED was seasoned for one year and

Superconductivity in Co-Layered LaCoSi

April 22, 2021
Author(s)
Zhengwen He, Rongjin Huang, Kaiyao Zhou, Ye Liu, Shibin Guo, Yuzhu Song, Zhongnan Guo, Shuxian Hu, Lunhua He, Qingzhen Huang, Laifeng Li, Jingyan Zhang, Shouguo Wang, Jiangang Guo, Xianran Xing, Jun Chen

A portable triaxial cell for beamline imaging of rocks under triaxial state of stress

April 21, 2021
Author(s)
Amer Syed, Yukie Tanino, Jacob LaManna, David L. Jacobson, Daniel S. Hussey, Eli Baltic, Genoveva Burca
With recent developments in direct imaging techniques using x-ray and neutron imaging, there is an increasing need for an efficient design of a test setup to study mechanical and/or the transport behaviour of porous rocks. Bespoke design from commercial

Accurate measurement of the through-plane water content of proton-exchange membranes using neutron radiography

April 21, 2021
Author(s)
Daniel S. Hussey, David L. Jacobson, Dusan Spernjak, Adam Weber, Rangachary Mukundan, Joseph Fairweather, Eric Brosha, John Davey, Jacob Spendelow, Rodney Borup
The water sorption of proton-exchange membranes (PEMs) was measured in situ using high-resolution neutron imaging in small-scale fuel-cell test sections. A detailed characterization of the measurement uncertainties and corrections associated with the

Average Soil Water Retention Curves Measured by Neutron Radiography

April 21, 2021
Author(s)
Daniel S. Hussey, David L. Jacobson, Chu-lin Cheng, Misun Kang, Juske Horita, sophie voisin, Hassina Bilheux, Warren Jeffery, Edward Perfect
Water retention curves are essential for understanding the hydrologic behavior of partially- saturated porous media and modeling flow transport processes within the vadose zone. In this paper we report direct measurements of the main drying and wetting

Blow-Down Calibration of a Large Ultrasonic Flow Meter

April 21, 2021
Author(s)
Aaron Johnson, Eric Harman, Joey Boyd
Oil and gas production industries use large (diameter > 0.8 m) ultrasonic flow meters (USMs) to measure exhaust gas from flare stacks, emissions from smokestacks, flow of natural gas, etc. Since most flow laboratories do not have compressors with

Cold Neutron Radiation Does Effects on a 6 LiF:ZnS(Ag) Neutron Detector with Wavelenght Shifting Fibers and SiPM Photodectector

April 21, 2021
Author(s)
Kevin NMN Pritchard, Daniel S. Hussey, A. Osovizky, Jeffrey B Ziegler, Louis Edward Binkley, Peter Tsai, Nancy Hadad, M. Jackson, C. Hurlbut, George M Baltic, Charles Majkrzak, Nicholas C. Maliszewskyj
A 6LiF:ZnS(Ag) based cold neutron detector with wavelength shifting (WLS) fibers and SiPM photodetector was developed at the NIST Center for Neutron Research for the CANDoR instrument (Chromatic Analysis Neutron Diffractometer or Reflectometer). To predict

Demonstration of focusing Wolter mirrors for neutron phase and magnetic imaging

April 21, 2021
Author(s)
Daniel S. Hussey, Han Wen, Huarui Wu, Thomas R. Gentile, Wangchun Chen, David L. Jacobson, Jacob LaManna, B. Khaykovich
Image-forming focusing mirrors were employed to demonstrate two different modalities of neutron imaging, phase imaging with a far-field interferometer, and magnetic-field imaging through the manipulation of the neutron beam polarization. For the phase

Demonstration of Small-Angle Neutron Scattering Measurements with a Nested Neutron-Focusing Supermirror Assembly

April 21, 2021
Author(s)
Huarui Wu, Zhiyuan Wang, Yao Zhang, Wenbo Mo, Pulin Bai, Kun Song, Zhong Zhang, Zhanshan Wang, Daniel S. Hussey, Yun Liu, Zhe Wang, Xuewu Wang
Neutron-focusing mirrors with both a nested structure and supermirror coatings enable a large collecting area, and consequently a large neutron current gain for mirror-based instruments. A nested neutron-focusing supermirror assembly has been fabricated

Design of a neutron microscope based on Wolter mirrors

April 21, 2021
Author(s)
Daniel S. Hussey, B. Khaykovich, Jeremy C. Cook, David L. Jacobson, Jacob LaManna, Kiranmayee Kilaru, Brian Ramsey, M. V. Gubarev
The predominate geometry for a neutron imaging experiment is that of a pinhole camera. This is primarily due to the difficulty in focusing neutrons due to the weak refractive index, which is also strongly chromatic. Proof of concept experiments

Effects of Cathode Corrosion on Through-Plane Water Transport in Proton Exchange Membrane Fuel Cells

April 21, 2021
Author(s)
Daniel S. Hussey, Joseph Fairweather, Dusan Spernjak, Adam Weber, David Harvey, Silvia Wessell, David L. Jacobson, Kateryna Artyushkova, Rangachary Mukundan, Rodney Borup
The corrosion of carbon in the electrode supports of proton-exchange-membrane fuel cells leads to electrode collapse, reduced active catalyst area, and increased surface hydrophilicity. While these effects have been linked to performance degradation over

Far-field interference of a neutron white beam and the applications to noninvasive phase-contrast imaging

April 21, 2021
Author(s)
Michael G. Huber, Daniel S. Hussey, Muhammad D. Arif, David L. Jacobson, Jacob LaManna, Wakana Ueno, Han Wen, Dmitry Pushin, Dusan Sarenac, David Cory, Houxun Miao, Takenao Shinohara, Joseph Parker
The phenomenon of interference plays a crucial role in the field of precision measurement science. Waveparticle duality has expanded the well-known interference effects of electromagnetic waves to massive particles. The majority of the wave-particle

High-resolution neutron depolarization microscopy of the ferromagnetic transitions inNi3Al and HgCr2Se4 under pressure

April 21, 2021
Author(s)
Daniel S. Hussey, Muhammad Abir, B. Khaykovich, C. Pfleiderer, Pau Jorba, Marc Seifert, Michael Schulz
We performed spatially resolved imaging of ferromagnetic transitions in Ni3Al and HgCr2Se4 crystals. These neutron depolarization measurements discovered bulk magnetic inhomogeneities in the ferromagnetic transition temperature with the spatial resolution
Displaying 4676 - 4700 of 74129